What
The research outcome will impact multiple fields on various time scales, including historical biogeochemistry, Earth system science, experimental geochemistry and it guides us how land plants may help mitigating future climate change, simply because the geological record stores information about global climatic changes in the past.
Why
The evolution of land plants ~400 million years ago marks a dramatic ecological shift in Earth history. In this research proposal, we will reconstruct the global oxygenation state of the oceans when ecologically distinct plants spread on the continents and use Earth system models to learn how land plants influence the composition of the atmosphere and oceans.
How
We will measure uranium isotopes in carbonate rocks deposited during critical events 480-360 million years ago allowing us to evaluate the average oxygenation state of the oceans from the rock record.